Physicochemical characterization of native and modified sodium caseinate- Vitamin A complexes

Area of Science:

• Food Science
• Protein Chemistry
• Nutritional Biochemistry

Background:

• Sodium caseinate is a key milk protein with potential applications in nutrient delivery systems.
• Vitamin A is an essential nutrient prone to degradation and bioavailability issues.
• Complexation with proteins can enhance the stability and delivery of lipophilic vitamins.

Purpose of the Study:

• To prepare and characterize native and modified sodium caseinate-vitamin A complexes.
• To investigate the physicochemical changes in sodium caseinate upon complexation with vitamin A.
• To evaluate the impact of protein modification and complexation method on complex properties.

Main Methods:

• Preparation of four types of sodium caseinate-vitamin A complexes (stirred native, stirred modified, reassembled native, reassembled modified).
• Characterization using particle size analysis, zeta potential measurements, turbidity analysis, and tryptophan fluorescence intensity.
• Microstructural analysis via microscopy and evaluation of electrophoretic mobility and RP-HPLC profiles.

Main Results:

• Complexation of vitamin A with sodium caseinate reduced turbidity and increased particle size and zeta potential.
• Structural modifications of both native and modified caseinate were confirmed upon vitamin A binding.
• Microscopy revealed distinct structural differences between spray-dried and freeze-dried proteins and their complexes.
• Electrophoretic mobility and RP-HPLC elution profiles remained unaffected by vitamin A binding.

Conclusions:

• Sodium caseinate effectively complexes with vitamin A, enhancing its stability and altering physicochemical properties.
• Protein modification and reassembly techniques influence the resulting complex structures.
• These findings suggest potential for improved vitamin A delivery systems using caseinate-based complexes.